let input_arr = ['100311']

let arr = new Array(10)
arr.fill(0)

let num = input_arr[0]
for(let c of num){
    let c_num =parseInt(c)
    arr[c_num]++
    
}
for(let i =0; i < arr.length; i++){
    if(arr[i]>0){
        console.log(`${i}:${arr[i]}`);
    }

}